Cultivation of anaerobic ammonium oxidation (anammox) bacteria in a continuous stirred tank reactor

Chang Ding, PhD

Scientist, Helmholtz Centre for Environmental Research

April 28, 2023 | 11 a.m. | 223 Jarvis Hall

Abstract

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Anaerobic ammonium oxidation (anammox) is a geologically important process that is responsible for the production of roughly 50% of nitrogen gas in the atmosphere. It is also a promising nitrogen removal strategy in wastewater treatment, requiring much less energy and material input. Traditionally, anammox bacteria were enriched and cultivated in biomass-retaining reactors such as sequencing batch reactors and membrane bioreactors. We showed that, cultivating anammox bacteria (genus “Candidatus Kuenenia”) is feasible with continuous stirred tank reactors (CSTRs) where the cells grow in planktonic form. Automated reactor operation and online monitoring of reactor performance enabled tight control of growth conditions and led to the highest ever growth rate for anammox bacteria (μ = 0.33 d-1). The CSTR reactor of anammox bacteria proved to be a powerful tool for investigating anammox physiology and biochemistry. With the help of the reactor, we gathered information on the physiological behaviors of anammox bacteria, obtained the complete genome of the anammox bacterium “Candidatus Kuenenia stuttgartiensis” strain CSTR1, and looked into the biochemical background of key anammox pathways. The reactor design has also been successfully applied to cultivate several other fastidious microorganisms.

Bio

Dr. Chang Ding obtained his Bachelor degree of Environmental Engineering in Tsinghua University in Beijing, China in 2008. He worked on isolation, physiological characterization, and genomics of organohalide respiring bacteria for his doctoral study in the lab of Professor Jianzhong He in National University of Singapore from 2008 to 2015 before he joined Professor Lorenz Adrian’s lab in UFZ Leipzig as a Humboldt fellow. Since 2021 he is a group leader in the Department of Environmental Biotechnology in UFZ. His current research focuses on anaerobic/anoxic microbial processes of environmental relevance.